Answer:
The order from largest to smallest:
Chromosome
Protein (Chromatid, Chromatin)
DNA
Gene
Nucleotide
Explanation:
DNA is the chemical that chromosomes and genes are made of. DNA itself is made up of four simple chemical units that are abbreviated as A, G, C, and T. These letters are used to form three letter words that cells can read.
A chromosome is simply a very long piece of DNA that cells can easily copy. Humans usually have 23 pairs of chromosomes. They are numbered 1-22 with the 23rd pair being either XX in girls or XY in boys.
A gene is a stretch of DNA on a chromosome that has the instructions for making a protein. Each chromosome has many genes with humans having over 22,000 genes in all. A gene's instructions for a protein are written in the three letter code I referred to before.
A protein is a molecular machine that does a specific job. Some proteins like amylase help us digest food. Others like opsins help us see colors. And still others like the globins help our blood take oxygen to and carbon dioxide away from our cells. Chromatin is a complex of nucleic acids (e.g. DNA or RNA) and proteins (e.g. histones). It was identified in 1882. Initially, it was thought of as just a colored substance in a nucleus, however, later it was found that chromatin is characterized as proteins attached to DNA, and DNA was identified as the carrier of genetic information (Ma, Kanakousaki, and Buttitta 2015). Thus, we can define chromatin as a substance consisting of DNA and associated proteins (known as histones).
